One of the things missing from the SDF tutorials is how to call regular phone numbers. You first need to be an ARPA member, which costs $36. It’s a one time payment, and then you’re an SDF member for life! Then it’s just $15/qtr for unlimited calls anywhere in the world.
Follow the steps on the VOIP tutorial page to get your SIP account set up with your app/phone of choice.
Calling North America is easy. You just need to prefix the 10-digit number with a 1. For example: 1 (208) 555-1234 It does not need a + in front. This will cause the call to fail. The same thing will happen if you do not have the 1 out front.
I have called Europe a few times now. For those of us in North America, we are used to prefixing European numbers with +011 or 011. You don’t need to do this when calling Europe. For example:
Calling Norway, country code 47: 47 585 66 972
So the country code followed by the 8 digit phone number… Pretty simple!